Probability-based bridge assessment

This paper describes the application of the newly developed Danish guideline for probability-based assessment of bridges to a beam and slab bridge that was built in 1935 and is located outside Copenhagen. The guideline, published by the Danish Roads Directorate in 2004, reflects a commitment to consider probability-based assessment for all bridge structures that have failed a deterministic assessment. For the structure analysed, modelling of the critical limit states is presented as are the statistical techniques employed in modelling the loads and resistances. The overall aim of the analysis was to achieve a higher load rating for the structure than that resulting from a traditional deterministic analysis. Ultimately the cost benefits to bridge owners/managers of performing a probabilistic assessment are apparent from the results, which provide a higher load rating for the bridge than were achieved through deterministic assessment. Although the guideline is intended to be applied in probability-based assessment of Danish bridges it is anticipated that it could equally be applied in other countries.